Critical issues in the use of vasoactive substances to assess lund microvascular injury.
Critical issues in the use of vasoactive substances to assess lund microvascular injury.
复制标题
使用血管活性物质评估隆德微血管损伤的关键问题。
DOI：
10.1111/j.1749-6632.1982.tb21391.x
复制
发表时间：
1982
影响因子：
5.2
通讯作者：
Mellins,RB
中科院分区：
文献类型：
--
作者：
Stalcup,SA;Turino,GM;Mellins,RB
The lung removes a number of vasoactive substances from mixed venous blood (TABLE 1). These substances represent several chemical classes, including cyclic nucleotides, peptides, amines, and prostaglandins. Although the lung will accept agents from several chemical groups, within a given chemical class the lung is quite selective in distinguishing between substances that differ very slightly in their composition or stru~ ture.'~ For example, although they are quite similar structurally, the lung removes norepinephrine from mixed venous blood while permitting passage of epinephrine. Angiotensin I1 is not affected by pulmonary passage, whereas its structurally similar precursor, angiotensin I, is nearly completely metabolized to the lower homologue. Because of such selectivity, because of the wide range of vasoactive substances metabolized, and because these substances have important biologic effects, considerable interest has developed in using the pulmonary extraction of vasoactive agents as a marker for lung inj~ ry. 2~ At present, all of these metabolic functions appear to be the property of a single cell type, the pulmonary endothelial cell.'Endothelial cells represent the single most common cell type in the lung, comprising from 30 to 40% of the total lung cells, of which there are about 40 different types. Structurally, the endothelial bed is apposed to alveolar lining cells, so that injury to the lung may be expected to be reflected in loss of endothelial cell function as well as in impairment in the lung's gas-exchanging function. Finally, there are only a limited number of ways in which disturbances in the lung microenvironment can be assessed, eg, measurements of blood gas tensions, end-expiratory gas tensions, and lung diffusing capacities all suffer from lack of sensitivity and specificity. For these reasons, the development of methods to assess lung injury based on endothelial cell functions holds considerable promise. Inherent in the attainment of this promise is the recognition of the several problems involved in the use of the various existing methods to assess injury, and these problems will be the focus of this review. Several types of model systems have been developed to assess lung injury using vasoactive substances. Principal among these models are lung-tissue homogenates, the isolated, perfused lung, the catheterized, intact animal, and, more recently, the use of isolated endothelial cells propagated in tissue culture. In addition, several different methodological approaches to assess injury have
